Ultra Low Power Technology:
ESP8266EX has been designed for mobile, wearable electronics and Internet of Things applications with the aim of achieving the lowest power consumption with a combination of several proprietary techniques. The power saving architecture operates mainly in 3 modes: active mode, sleep mode and deep sleep mode.By using advance power management techniques and logic to power-down functions not required and to control switching between sleep and active modes, ESP8266EX consumes about than 60uA in deep sleep mode (with RTC clock still running) and less than 1.0mA (DTIM=3) or less than 0.5mA (DTIM=10) to stay connected to the access point.
When in sleep mode, only the calibrated real-time clock and watchdog remains active. The real-time clock can be programmed to wake up the ESP8266EX at any required interval.
The ESP8266EX can be programmed to wake up when a specified condition is detected. This minimal wake-up time feature of the ESP8266EX can be utilized by mobile device SOCs, allowing them to remain in the low-power standby mode until Wi-Fi is needed.In order to satisfy the power demand of mobile and wearable electronics, ESP8266EX can be programmed to reduce the output power of the PA to fit various application profiles, by trading off range for power consumption.

ESP8266 series modules As following types:
ESP - 01 includes two versions, one Blue version and a black version, functions and Pin is same, only the mainboard.it is different the color of mainboard . the AI - thinker have shut down Blue version now, ESP-01 are altogether 8 pin counts, The external size of the module is 14.3mm*24.8mm*3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.
The antenna applied on this module is a 3DBi PCB-on-board antenna.

ESP-02 are altogether 8 pin counts, The external size of the module is 14.9mm *16.3 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.

ESP-03 are altogether 14 pin counts, The external size of the module is 17.3mm *12.1 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.
The antenna applied on this module is a ceramic antenna.

ESP-04 are altogether 14 pin counts, The external size of the module is 14.7mm *12.1 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.

ESP-05 are altogether 5 pin counts, The external size of the module is 14.2mm *14.2 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.

ESP-06 are altogether 5 pin counts, The external size of the module is 16.2mm *13.2 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.

ESP-07 are altogether 5 pin counts, The external size of the module is 16mm *21.2 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.
The antenna applied on this module is a ceramic antenna.

ESP-08 are altogether 5 pin counts, The external size of the module is 16mm *18.5 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.

ESP-09 are altogether 20 pin counts, The external size of the module is 10mm *10 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.

ESP-10 are altogether 5 pin counts, The external size of the module is 16mm *18.5 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.

ESP-11 are altogether 8 pin counts, The external size of the module is 16mm *18.5 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 1 MB,the package size of which is SOP-210mil.

ESP-12 are altogether 18 pin counts, The external size of the module is 16mm *18.5 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 4 MB,the package size of which is SOP-210mil.
The antenna applied on this module is a 3DBi PCB-on-board antenna.

ESP-12E are altogether 16 pin counts, The external size of the module is 16mm *24 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 4 MB,the package size of which is SOP-210mil.
The antenna applied on this module is a 3DBi PCB-on-board antenna.

ESP-12F are altogether 18 pin counts, The external size of the module is 16mm *24 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 4 MB,the package size of which is SOP-210mil.
The antenna applied on this module is a 3DBi PCB-on-board antenna.

ESP-13 are altogether 18 pin counts, The external size of the module is 18mm *20 mm *3mm .The type of Flash integrated in this module is an SPI flash, the capacity of which is 4 MB,the package size of which is SOP-210mil.
The antenna applied on this module is a 3DBi PCB-on-board antenna.

ESP-14 are altogether 18 pin counts, The external size of the module is 16mm *24 mm *3mm .the capacity of which is 1MB.ESP-14 module has a built-in powerful STMs8003F3P6 chips and wifi ESP8266, pick out all the pins, serial port can connected tthe serial port of the ESP8266, users can write STM8 program, through the AT command control WIFI Internet capability.